Campaigns · Wilson's Creek, Fort Donelson, Shiloh, Corinth and Atlanta
Thomas William Sweeny was born on December 25, 1820, in County Cork, Ireland. He and his widowed mother moved to the United States when young Sweeny was 12 years old, and they eventually settled in New York City. He worked for a law publisher, and joined the Baxter Blues, a militia company, in 1843. His unit fought in the Mexican War, as Company A/2d New York Volunteers, and Sweeny's right arm was amputated after it was wounded.
After he recuperated, he fought against Native Americans in the Southwest and on the Great Plains until the beginning of the Civil War. When the Civil War began, Sweeny was stationed in St. Louis, Missouri, and became a brigadier general of Missouri's short-term volunteers. While fighting under Brig. Gen. Nathaniel Lyon at Wilson's Creek, he was wounded and carried off the field. He was mustered out of the volunteer service, but reentered in January of 1863.
Sweeny led troops at Fort Donelson, was wounded at Shiloh and fought at Corinth. Promoted to brigadier general of volunteers on March 16, 1863, he led a division in the Atlanta Campaign. During the campaign, his long-standing conflicts with Maj. Gen. Grenville M. Dodge and Brig. Gen. John W. Fuller came to a head. After an argument and fight, Dodge arrested Sweeny. A military court, however, acquitted Sweeny in January of 1865, and he remained in the army.
In 1886, he led a group of Irishmen in an attempt to capture Canada from the British, but was thwarted by US officials and arrested. He left the army in May of 1870, retiring at the rank of brigadier general of Regulars..Sweeny lived in Astoria, on New York's Long Island, until his death on April 10, 1892.